This invention relates to the filtration field, and more particularly, to a disposable vacuum filtration funnel with an integral prefilter. Commercially available disposable vacuum filtration devices consist of a funnel that contains a microporous filter sealed to the funnel. The funnel may be attached to a disposable bottle, a reusable bottle, or to a manifold, so that the downstream side of the microporous filter is in fluid flow communication with the bottle or manifold. Fluid to be filtered is placed into the disposable funnel, and a negative pressure (i.e. vacuum) is applied to the bottle or manifold to which the disposable funnel is attached. The negative pressure in the bottle or manifold sucks the fluid through the microporous filter into the bottle or manifold. The pore size of the microporous filter is normally between 0.2 μm and 1.5 μm. The maximum volume of fluid that can be filtered by this type of filtration apparatus before the microporous filter becomes fouled, is limited by the surface area of the microporous filter. To increase the maximum volume of fluid that can be filtered by such an apparatus, the surface area of the microporous filter must be increased, which means that that the funnel size must be increased, which increases the cost of manufacturing the apparatus. Some manufacturers suggest placing a single layer of prefilter pad on top of the microporous filter to extend the throughput of the microporous filter. Because the prefilter pad will not be sealed to the disposable funnel, fluid to be filtered can bypass the prefilter, therefore the increase in throughput will be limited. It is therefore an object of the present invention to provide a means to add a multi-layer prefilter sealed to the disposable funnel, to increase the maximum volume of fluid that can be filtered by such an apparatus without increasing the surface area of the microporous filter.